For many years, great effort has been made to increase photographic sensitivity of silver halide photographic photosensitive materials (hereinafter referred to as “photosensitive material”). In a silver halide photographic emulsion, a sensitizing dye, adsorbed on the surface of silver halide grains, absorbs a light irradiated into a photosensitive material, and the absorbed light energy is transmitted to the silver halide grains, displaying photosensitivity. Accordingly, in spectral sensitization for the silver halide, it is assumed that the light energy transmitted to the silver halide can be increased by increasing the light absorption rate per unit of grain surface area of silver halide grains, thereby leading to increased spectral sensitivity. The light absorption rate on the surface of silver halide grains can be enhanced by increasing the quantity of a spectral sensitizing dye adsorbed per unit of grain surface area.
However, there is a limit to the quantity of a spectral sensitizing dye that can be adsorbed on the surface of silver halide grains, such that it is difficult to adsorb a larger quantity of dye chromophore than a mono-layer-saturated adsorption; namely, a single-layer adsorption. Accordingly, at the present time, the absorption rate of incident photons by individual silver halide grains in the spectral sensitization region is still unsatisfactory.
As a method to solve these problems, there are many proposals for adsorbing a grater quantity of sensitizing dyes than a single-layer adsorption. For example, in the Description of the Conventional Art of JP-A-2002-23294 (“JP-A” means unexamined published Japanese patent application), prior art documents and patents related to the afore-mentioned method are described. Recently, in particular, advances in photographic sensitivity by a multi-layer adsorption, owing to a combination of a specific cationic dye and a specific anionic dye, have been tried (see, for example, JP-A-10-239789, JP-A-10-171058, and EP0985965). However, these methods tend to increase residual color resulting from sensitizing dyes.
In addition, in the remarkable progress of digital cameras and color printers, processing of a silver halide photographic photosensitive material (especially a silver halide color photographic photosensitive material) that is able to rapidly provide a high-quality image to users has been demanded. However, if the processing time in the conventional processing method is simply reduced, the processing terminates before sensitizing dyes in the photosensitive material are sufficiently washed out thereof. Accordingly, there is a problem that the image becomes unacceptably colored (stained) by a substantial amount of sensitizing dyes that remains in the white ground portion of a color print (this stain is called residual color). Further, also in color negative films, increased density in the minimum density area, owing to residual color, breaks color balance and makes providing a proper print difficult.
Further, the use of tabular silver halide grains, is an important fundamental technology in a high-sensitivity photosensitive material for shooting in recent years. If tabular silver halide grains, particularly tabular silver halide grains having a high aspect ratio (hereinafter referred to as tabular grains), are used, as their photographic property, they have a high ratio of surface area to volume, and therefore, the quantity of sensitizing dyes used per unit volume can be increased. This results in effects of enhanced sensitivity and ratio of sensitivity to granularity, and thereby higher color sensitization sensitivity can be obtained (see, for example, U.S. Pat. No. 5,494,789). The term “aspect ratio” used herein refers to the ratio of diameter to thickness of the tabular grain. “Diameter of the tabular grain” refers to the diameter of a circle having an area equivalent to the projected area of the said grain, when an emulsion is observed with optical or electronic microscope. Further, the thickness of the tabular grain refers to the distance between two parallel planes that constitute the said grain.
However, the use of tabular grains increases the quantity of sensitizing dyes remaining in the photosensitive material after processing. As such, depending on the processing conditions, the quantity of residual sensitizing dyes sometimes increases to an extent that it cannot be neglected, and which causes phenomena in which the density of the minimum density area of a color negative film increases, and the highlight area of a color reversal film becomes colored.
Additionally, selenium sensitization of a silver halide emulsion is also useful for advances in photographic sensitivity, and many selenium compounds are known as selenium-sensitizing agents (see, for example, JP-A-4-109240). However, also in this method, there is a problem resulting from the residual sensitizing dyes.
As an example of the method of eliminating residual color resulting from a sensitizing dye, for example, there is disclosed a method of using a bistriazinyl aminostylbene disulfonic acid compound. This method has been used over a wide range in the processing of color photographic photosensitive material (for example, see Research Disclosure (hereinafter abbreviated as RD) No. 20733). Further, for example, there is disclosed a bistriazinylaminostylbene disulfonic acid compound that is excellent in solubility and able to reduce residual color even in time-reduced processing (for example, see JP-A-6-329936).
As shown in the above, as a method of reducing a residual color, there are known methods of adding a particular compound to a processing solution. However, there is no known method in which a silver halide photographic photosensitive material, having a dye chromophore that is multilayer-adsorbed on the silver halide, is processed with such a processing solution.
Further the bistriazinylaminostylbene disulfonic acid compound is generally added to a developing solution, to thereby obtain a residual-color reducing effect. However, when added to a fixing solution, the said compound deteriorates in the presence of components in the fixing solution, such that it is difficult to maintain performance stably.
In addition, the bistriazinylaminostylbene disulfonic acid compound, which is originally a fluorescent brightening agent, sometimes imparts an unnecessary fluorescent whitening property to a photosensitive material after processing.
Further, as compounds other than the bistriazinylaminostylbene disulfonic acid compound, for example, these are disclosed bisarylaminotriazine compounds (for example, see U.S. Pat. No. 6,153,364). However, because these compounds are added to a developing solution, a bleaching solution, or a fixing solution, deterioration of the components resulting from long-term usage makes it difficult to maintain image quality.
As mentioned above, there is a demand for a silver halide photosensitive material that has high sensitivity and low residual color, and a processing method of the photosensitive material, or an image-forming method using the photosensitive material.